A value of sinh x or cosh x is given. Use the definitions and the identity cosh 2 x - sinh 2 x = 1 to find the value of the
other indicated hyperbolic function.
-$\cosh x = \frac { 17 } { 8 } , x

Question

A value of sinh x or cosh x is given. Use the definitions and the identity cosh 2 x - sinh 2 x = 1 to find the value of the
other indicated hyperbolic function.
-$\cosh x = \frac { 17 } { 8 } , x < 0 , \operatorname { sech } x =$
A) $- \frac { 289 } { 64 }$
B) $\frac { 8 } { 17 }$
C) $- \frac { 8 } { 15 }$
D) $\frac { 15 } { 17 }$

Quizplus · Accepted Answer

The hyperbolic secant, $\operatorname{sech} x$, is defined as the reciprocal of the hyperbolic cosine, $\cosh x$. Therefore, $\operatorname{sech} x = \frac{1}{\cosh x} = \frac{1}{\frac{17}{8}} = \frac{8}{17}$.

A Value of Sinh X or Cosh X Is Given cosh⁡x=178,x<0,sech⁡x=\cosh x = \frac { 17 } { 8 } , x < 0 , \operatorname { sech } x =coshx=817​,x<0,sechx=

A Value of Sinh X or Cosh X Is Given $\cosh x = \frac { 17 } { 8 } , x < 0 , \operatorname { sech } x =$